This invention relates to a substrate treating apparatus for performing a series of treatments of substrates such as semiconductor wafers, glass substrates for liquid crystal displays, glass substrates for photomasks, and substrates for optical disks (hereinafter called simply “substrates”).
Conventionally, this type of substrate treating apparatus is used to form a resist film on substrates and develop the substrates exposed in a separate exposing machine. The apparatus includes a treating section having, arranged therein, a coating block for forming film such as resist film, a developing block for developing the substrates, and so on. Each treating block includes a single main transport mechanism and various treating units. The main transport mechanism of each treating block, while transporting substrates to the treating units in that treating block, transfers the substrates through receivers to and from the main transport mechanism of another, adjacent, treating block to carry out a series of treatments of the substrates (as disclosed in Japanese Unexamined Patent Publication No. 2003-324139, for example).
The conventional apparatus with such a construction has the following drawbacks.
In the conventional apparatus, when the main transport mechanism of one of the treating blocks breaks down or otherwise becomes unable to transport substrates (abnormal state), it becomes altogether impossible to transport the substrates to and from other, adjoining, treating blocks. Only a single route (transport path) is available for transporting the substrates between the treating blocks, and thus transporting is lacking in flexibility. Consequently, there occurs an inconvenience that the substrates cannot be treated at all even though the main transport mechanisms of the other treating blocks are in a normal condition.